1 /* $NetBSD: tty_tty.c,v 1.11 1994/10/30 21:48:05 cgd Exp $ */ 2 3 /*- 4 * Copyright (c) 1982, 1986, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)tty_tty.c 8.2 (Berkeley) 9/23/93 36 */ 37 38 /* 39 * Indirect driver for controlling tty. 40 */ 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/conf.h> 44 #include <sys/ioctl.h> 45 #include <sys/proc.h> 46 #include <sys/tty.h> 47 #include <sys/vnode.h> 48 #include <sys/file.h> 49 50 #define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL) 51 52 /*ARGSUSED*/ 53 cttyopen(dev, flag, mode, p) 54 dev_t dev; 55 int flag, mode; 56 struct proc *p; 57 { 58 struct vnode *ttyvp = cttyvp(p); 59 int error; 60 61 if (ttyvp == NULL) 62 return (ENXIO); 63 VOP_LOCK(ttyvp); 64 #ifdef PARANOID 65 /* 66 * Since group is tty and mode is 620 on most terminal lines 67 * and since sessions protect terminals from processes outside 68 * your session, this check is probably no longer necessary. 69 * Since it inhibits setuid root programs that later switch 70 * to another user from accessing /dev/tty, we have decided 71 * to delete this test. (mckusick 5/93) 72 */ 73 error = VOP_ACCESS(ttyvp, 74 (flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p); 75 if (!error) 76 #endif /* PARANOID */ 77 error = VOP_OPEN(ttyvp, flag, NOCRED, p); 78 VOP_UNLOCK(ttyvp); 79 return (error); 80 } 81 82 /*ARGSUSED*/ 83 cttyread(dev, uio, flag) 84 dev_t dev; 85 struct uio *uio; 86 int flag; 87 { 88 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 89 int error; 90 91 if (ttyvp == NULL) 92 return (EIO); 93 VOP_LOCK(ttyvp); 94 error = VOP_READ(ttyvp, uio, flag, NOCRED); 95 VOP_UNLOCK(ttyvp); 96 return (error); 97 } 98 99 /*ARGSUSED*/ 100 cttywrite(dev, uio, flag) 101 dev_t dev; 102 struct uio *uio; 103 int flag; 104 { 105 register struct vnode *ttyvp = cttyvp(uio->uio_procp); 106 int error; 107 108 if (ttyvp == NULL) 109 return (EIO); 110 VOP_LOCK(ttyvp); 111 error = VOP_WRITE(ttyvp, uio, flag, NOCRED); 112 VOP_UNLOCK(ttyvp); 113 return (error); 114 } 115 116 /*ARGSUSED*/ 117 cttyioctl(dev, cmd, addr, flag, p) 118 dev_t dev; 119 u_long cmd; 120 caddr_t addr; 121 int flag; 122 struct proc *p; 123 { 124 struct vnode *ttyvp = cttyvp(p); 125 126 if (ttyvp == NULL) 127 return (EIO); 128 if (cmd == TIOCSCTTY) /* XXX */ 129 return (EINVAL); 130 if (cmd == TIOCNOTTY) { 131 if (!SESS_LEADER(p)) { 132 p->p_flag &= ~P_CONTROLT; 133 return (0); 134 } else 135 return (EINVAL); 136 } 137 return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p)); 138 } 139 140 /*ARGSUSED*/ 141 cttyselect(dev, flag, p) 142 dev_t dev; 143 int flag; 144 struct proc *p; 145 { 146 struct vnode *ttyvp = cttyvp(p); 147 148 if (ttyvp == NULL) 149 return (1); /* try operation to get EOF/failure */ 150 return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p)); 151 } 152